Some air cleaners are configured to remove particulate matter from air using a process sometimes referred to as electrostatic precipitation. Some air cleaners comprise electrostatic precipitators configured to perform differently in response to the characteristics of the electrical energy supply. In some cases, an air cleaner may comprise a fan configured to draw or push air through a passage of the air cleaner. In other cases, an air cleaner may be used in combination with a heating, ventilation, and/or air conditioning system (HVAC system) so that a fan of the HVAC system may be operated to draw or push air through a passage of the air cleaner.